BY WILLIAM A. HASWELL. 



331 



except the first six, which have only dorsal setae, have each a 

 bundle of four fine, tapering dorsal setae and three stouter, short 

 ventral setae, which are curved at the ends. (Plate xxvu. fig. 9.) 

 The dorsal setae are in fan-like groups directed forwards and out- 

 wards. 



The body wall is tolerably firm. The surface is covered with 

 closely-set papillae, which vary in size, some being elongate, others 

 very short ; a number of those around the bases of the anterior 

 large setae are very long and slender, with slightly enlarged 

 rounded ends : a detailed account of the papillae is given further 

 on. 



The head (fig. 2) consists of a stout base, bearing distally a 

 pair of tentacles, and a pair of branchiferous lobes. The base is 

 8 mm. in length, and at its posterior end is about half the thick- 

 ness of the anterior part of the body, narrowing slightly towards 

 its distal end ; closely embraced behind by the bases of the ring 

 of large anterior setae and by the elongated papillae ; its surface 

 is dotted over with papillae similar to those covering the body, 

 but smaller. It consists of the greatly produced peristomium 

 surrounded, as by a sheath, by a thin prolongation of the first body- 

 segment. The praestomium is produced in front laterally into 

 the compressed bases of the branchiferous lobes ; mesially in 

 front is a small lobe bearing two pairs of eyes ; in front of the 

 mouth are borne the two tentacles. The branchiferous lobes are 

 somewhat club-shaped, a little shorter than the head, and covered 

 with branchiae, about sixty on each. The two tentacles are 

 cylindrical, longitudinally grooved bodies, which taper slightly 

 towards the end, rather longer than the head, but scarcely a 

 third of the diameter, devoid of papillae. 



The total length of the specimen, including the setae, was 

 5 cm. ; of the body excluding setae and head-lobe, 2 J cm. The 

 head lobe with the branchiae was 1*2 cm. in length. The greatest 

 breadth of the body was -5 cm. ; the breadth at the posterior end 

 •2 cm. 



Specimen B (fig. 3). — The form of the body is approximately 

 cylindrical, broadest near the anterior end and gradually tapering 







